[Secondary hypothermia with brain tumor in an elderly woman and the circadian rhythm of body temperature].

An elderly case of secondary hypothermia associated with brain tumor was reported. An 84-year old woman developed hypothermia. Although her rectal temperature remained below 37 degrees C, the circadian rhythm of rectal temperature was preserved. Brain computerized tomography (CT) and brain magnetic resonance imaging (MRI) revealed a solitary brain tumor involving the hypothalamus. It appears that her hypothermia may not be due to inability to thermoregulate but to stem from her abnormal target temperatures. Body temperature is normally controlled at around 37 degrees C, but in this patient thermoregulation might have been reset at a lower temperature.